This invention is concerned with improvements in or relating to circular knitting machines, and more particularly the invention relates to an automatic device for positioning the control cams in needle selecting cylinders.
The present invention allows the use of a single profile cam rather than a several profile cam as shown in U.S. Pat. No. 3,766,753. In addition, the cam according to the present invention is not positioned in a vertical direction, but rather in a horizontal direction, so that the springs associated with cam positioning do not have to accommodate the weight of the cam itself, and thus eliminating the possibility that a lack of precision in the vertical positioning of the cam might adversely affect proper positioning of the follower.
As well known, a circular knitting machine substantially comprises a fixed frame carrying a needle cylinder cooperating upon rotation with a plurality of small drawing or needle selecting cylinders carried by said frame parallel and about the periphery of said needle cylinder for selecting through suitable pins or pegs the needles for the knitting machine.
These needle selecting cylinders can be maintained stationary or rotated in a predetermined direction to select the various knitting needle according to the work program and the desired pattern on the knitted fabric being formed.
The rotation through one or more steps of each needle selecting cylinder, wherein a step is meant for the spacing between two adjoining rows of pins in each of said needle selecting cylinders, is provided by a cam controlled device carried by the needle cylinder. Therefore, the control cam should be maintained stationary, radially forward or backward moved depending on the greater or smaller rotation to be imparted to each of the needle selecting cylinders at each rotation of said needle cylinder.